A major focus of our studies will be the regulation of transcription and of stability of mRNAs specific for prespore and prestalk cells, as well as mRNAs synthesized throughout growth and differentiation. These studies will include mapping and sequencing of genomic DNA clones; in vitro studies of regulated mRNA synthesis and destruction; in situ detection of mRNAs; and determination of the commitment of prespore and prestalk cells. We will attempt to elucidate the intracellular "second messenger(s)" that mediate the effect of the extracellular hormone, cAMP, on synthesis and stability of regulated mRNAs; and to detect specific cell surface proteins that are required for induction of gene expression in multicellular aggregates. Finally, we shall study the structure and regulation of transcription and mRNA processing of a class of repetitive DNA sequences that is expressed as mRNA only during differentiation of heat shock.